This is the concept of trajectories;
We are required to calculate the time taken for the base ball whose distant to reach the maximum height has been modeled by h=-16t^2+64t+4.2 took to hit the ground. Here we proceed as follows;
At the time when the base ball hits the ground the height,h=0
Thus;
-16t^2+64t+4.2=0
this is a quadratic equation, to solve the quadratic equation we use the formula;
t=[-b+/- sqrt(b^2-4ac)]/(2a)
where;
a=-16,b=64, c=4.2
thus substituting the values in our formula we get:
t=[-64+/-sqrt(64^2-4*(-16)*4.2)]/(-16*2)
t=[-64+/- sqrt(4364.8)]/(-32)
t=[-64+/-66.1]/(-32)
t=4.1 or-0.1
thus the we take the positive value t=4.1 and we conclude that the time taken for the ball to hit the ground was 4.1 seconds
Answer: a. 5/12 b. 10 hours
Step-by-step explanation:
5/8 x 2/3 = 10/24 = 5/12
she spends 5/12 of the day awake at home
if a day has 24 hours then 5/12 of that is 5/12 x 24 = 10
so she spends 10 hours awake at home
There is only one number that is equal to the absolute value of 15.
That number is 15.
But wait !
There are two different numbers WHOSE ABSOLUTE VALUES
are both 15.
Those numbers are 15 and -15 .
Answer:
Step-by-step explanation:
Notice that in the second equation, the coefficient of 
is 
times greater than in the first. Therefore, by making the coefficient of 
in the second equation times greater than in the first, it's impossible to only isolate one variable.
Therefore, when 
, there are no solutions to this system.
